Enzyme specificity is given by

Enzyme specificity is given by ?
a) Km
b) Vrm„
c) Both
d) None
Correct Answer - A
Ans. is ‘a’ i.e., Km.
The Km of an enzyme is the concentration of the substrate that
enables the enzyme to function at half maximum activity and is
therefore a measure of the specificity of a substrate.for the
enzyme" Clinical biochemistry
Actually enzyme specificity is not measured by Km alone.
It is measured by the ratio Kcat/Km which is a second order rate
constant for the reaction between substrate and free enzyme.
This ratio is important, for it provides a direct measure of enzyme
efficiency and specificity.
Note : Kcat is turnover number and measures the rate of the catalytic
process.